This from an editorial  in today’s Wall Street Journal:
Everyone knows that Intel, Yahoo, Google, eBay and Sun
Microsystems are wildly successful U.S. technology companies. Less well
known is that immigrant entrepreneurs played a role in founding each
one — and a whole lot of others.
After an election season that featured an unfortunate
amount of anti-immigration posturing, a new study from the National
Venture Capital Association is a welcome reminder that foreign workers
make their fair share of important contributions to our economy.
Titled "American Made: The Impact of Immigrant
Entrepreneurs and Professionals on U.S. Competitiveness," the report
found that "Over the past 15 years, immigrants have started 25 percent
of U.S. public companies that were venture-backed." These businesses
employ some 220,000 people in the U.S. and have a current market
capitalization that "exceeds $500 billion, adding significant value to
the American economy."
Here’s a link  to the study.